Biotechnology Research Institute , Chinese Academy of Agricultural Sciences , 12 Zhongguancun South Street , Beijing 100081 , P.R. China.
Southwest Center for Natural Products Research , University of Arizona , 250 East Valencia Road , Tucson , Arizona 85706 , United States.
J Am Chem Soc. 2019 Mar 13;141(10):4355-4364. doi: 10.1021/jacs.8b12967. Epub 2019 Feb 27.
O-Methylation modulates the pharmacokinetic and pharmacodynamic (PK/PD) properties of small-molecule natural products, affecting their bioavailability, stability, and binding to targets. Diversity-oriented combinatorial biosynthesis of new chemical entities for drug discovery and optimization of known bioactive scaffolds during drug development both demand efficient O-methyltransferase (OMT) biocatalysts with considerable substrate promiscuity and tunable regioselectivity that can be deployed in a scalable and sustainable manner. Here we demonstrate efficient total biosynthetic and biocatalytic platforms that use a pair of fungal OMTs with orthogonal regiospecificity to produce unnatural O-methylated benzenediol lactone polyketides. We show that rational, structure-guided active-site cavity engineering can reprogram the regioselectivity of these enzymes. We also characterize the interplay of engineered regioselectivity with substrate plasticity. These findings will guide combinatorial biosynthetic tailoring of unnatural products toward the generation of diverse chemical matter for drug discovery and the PK/PD optimization of bioactive scaffolds for drug development.
O-甲基化调节小分子天然产物的药代动力学和药效动力学（PK/PD）特性，影响其生物利用度、稳定性和与靶标的结合。为了药物发现和开发过程中已知生物活性支架的优化，需要具有相当的底物宽泛性和可调节的区域选择性的高效 O-甲基转移酶（OMT）生物催化剂，这些催化剂可以以可扩展和可持续的方式进行部署。在这里，我们展示了使用一对具有正交区域特异性的真菌 OMT 的有效全生物合成和生物催化平台，以生产非天然的 O-甲基化苯二醇内酯聚酮。我们表明，合理的、基于结构的活性位点腔工程可以重新编程这些酶的区域选择性。我们还研究了工程化的区域选择性与底物可塑性的相互作用。这些发现将指导非天然产物的组合生物合成修饰，以生成用于药物发现的多样化化学物质和用于药物开发的生物活性支架的 PK/PD 优化。
